Short answer: no. There is no reliable or accepted way to convert between human and pet glucose meter numbers, and trying to do so is not recommended by experienced caregivers on the Feline Diabetes Message Board (FDMB). To the best of current knowledge and long-standing caregiver experience, no conversion formula exists. Human and pet meters are calibrated differently and will naturally produce different numbers from the same cat, but those numbers are not meant to be translated into each other. Conversion formulas are inconsistent, unreliable, and can lead to dosing errors. What matters is using one meter consistently and interpreting results with your veterinarian using guidelines written for that meter type.
Why This Question Comes Up So Often
Caregivers managing feline diabetes frequently notice that human glucose meters and pet-specific meters produce different numbers from the same cat. This often leads to the assumption that one reading must be “converted” to match the other. The concern is understandable, but the premise is flawed. The meters are not interchangeable scales, and conversion introduces more risk than clarity.
The Difference Between Human and Pet Glucose Meters
Human glucose meters are calibrated for human blood chemistry. Pet meters are calibrated for animal blood, including cats. Cats have a different glucose distribution between plasma and red blood cells compared to humans. Because of this, caregivers have reported pet meters typically reading higher than human meters when measuring feline blood.
This difference is expected. It does not mean one meter is wrong. It means they are designed around different assumptions.
Why Veterinarians Often Recommend Pet-Specific Meters
Veterinarians often recommend pet-specific glucose meters because they are calibrated for animal blood and align more closely with the reference ranges and equipment used in veterinary clinics, which keeps home readings consistent with what the vet expects to see. There is also a liability and standardization factor, as pet meters are designed, marketed, and approved specifically for animal use, whereas human meters are technically used off-label in cats. What is often overlooked is that pet glucose meters are a relatively recent development in feline diabetes care. For many years, and throughout the early growth of online feline diabetes communities, caregivers successfully managed diabetic cats using human meters because pet meters either did not exist or were not widely accessible. The preference for pet meters reflects calibration and clinical convenience, not a requirement for safe or effective home glucose monitoring.
Cost and Long-Term Accessibility of Pet Meters
Pet-specific glucose meters and their test strips are typically more expensive than human meters, and ongoing strip costs can add up quickly for caregivers testing multiple times per day. Human meters are widely available at local pharmacies and big-box stores, often with lower strip prices and fewer supply disruptions. While cost alone should not determine medical decisions, we’ve seen long-term affordability and easy access to supplies play a role in whether caregivers can test consistently, which can directly impact safety and glucose control.
See our other article: Choosing a Glucose Meter for Your Diabetic Cat
Why Human Meters Usually Read Lower in Cats
In cats, a greater proportion of glucose is found in plasma rather than inside red blood cells. Veterinary meters are calibrated to account for that, so they display higher numbers. Human meters are not adjusted for this difference, so they generally report lower values in cats, especially at higher glucose ranges. The gap between meters is not fixed. It can change across the glucose spectrum and varies by device.
The Problem With Conversion Formulas
Over the years, many conversion formulas and charts have circulated claiming to translate human meter readings into pet meter numbers. These formulas usually assume a consistent percentage difference between meters. That assumption is incorrect.
The difference is not linear, and both human and pet meters already allow a margin of error. Applying a conversion formula compounds that uncertainty. A number that looks “precise” after conversion is often less accurate than the original reading.
Why Converting Numbers Can Be Dangerous
Conversion encourages caregivers to second-guess safe readings, misjudge nadirs, or potentially wrongly adjust insulin doses. A converted number may appear higher or lower than expected and trigger unnecessary action. This is especially risky when caregivers chase converted targets rather than following meter-specific guidelines.
Two meters can show different numbers while both are operating normally.
Consistent use of the same meter matters far more than the absolute number it displays. Trends over time show how a cat responds to insulin, food, and timing. Those trends remain valid within the context of a single meter.
A curve generated on a human meter is internally consistent. A curve generated on a pet meter is internally consistent. Mixing or converting between them breaks that consistency.
How Dosing Guidelines Handle Meter Differences
Well-established and research-backed dosing methods on the Feline Diabetes Message Board (FDMB) account for meter differences by using different safety thresholds for human meters versus pet meters. For a human meter, that number is 50 mg/dL and for a pet meter that number is 68 mg/dL. For international blood glucose numbers, see this conversion tool. These thresholds are not conversions. They are guardrails designed to keep cats safe based on how each meter type reads in real-world use.
What to Expect When Switching Meters
If you switch from a human meter to a pet meter or vice versa, expect the numbers to change immediately. That change does not mean your cat’s diabetes control suddenly worsened or improved. It means the calibration changed. When switching meters, establish a new baseline and watch trends going forward. Do not try to translate old numbers into the new meter’s range. If you keep track of your cat’s blood glucose in our spreadsheet, you will need to have the color coding changed to reflect the change in meter.
Conclusion
You do not need a conversion between human and pet glucose meters for cats. Conversion formulas are unreliable, misleading, and unnecessary. Choose one meter, use it consistently, follow guidelines written for that meter type and your veterinarian, and base decisions on trends.
